The Flow Cytometry Laboratory is located in a 400 square foot laboratory, K4/535, with an adjacent office, K4/563D. Analyses requiring both single and dual laser excitation and cell sorting services are offered to investigators. A wide range of cytometric tools are available including measurements of cell size, cell cycle, intracellular CA++ and pH, and cell kinetics, as well as of standard surface and intracellular phenotypes. In addition to maintaining and assisting in the operation of equipment, the staff are involved in the development of new protocols and methodology and assist investigators in specific experimental design. Technical assistance on sample preparation, the operation of the instruments, data analysis, and interpretation is available on an individual basis. All facility computers are connected via the University network, including those available for off-line data analysis.